Brake



April 28, 1936. R. s. EEG@ Y 2,038,707

BRAKE l Filed June lO, 1951 2 Sheets-Sheet 2 31a/vento@ Patented Apr. 28, 1936 UNITED STATES 2,038,707 BRAKE Russell S. Begg,

Midland Steel Ohio, a corporation Steeldraulic Brake Corporation Cleveland, Ohio, assignor to The Products Company, Cleveland,

of Ohio, as trustee for Application June 10, 1931, Serial No. 543,312

30 Claims.

More specifically this invention is directed to the provision of a cable actuated brake expanding mechanism that includes a horizontally acting toggle arranged between the shoe ends adapted to lo bc spread by means of a linkage consisting of a link pivotally connected to the center pin of the toggle and to one arm of a bell crank lever having a sliding pivot on an .upset portion oi the apron. The othery arm of the crank which lies exteriorly of the brake drum is connected to the brake operating cable arranged alongside the apron and also exteriorly of the drum. The exposed parts of the cable and bell crank are protected from the elements by means of a dust 20 housing that is of novel form and provides a rm secure seat for the end of the cable conduit. In addition, this invention contemplates a novel arrangement of the thrust pins connecting the ends of the brake shoe to the toggle mechanism, whereinone of the pins is set atV an angle to the other with the shoe in unexpanded position, the theory being that when the shoe moves toward expanded position the pins will tend to assume parallel positions to thereby relieve binding on the toggle at the instant of greatest expansive effort to thereby reduce friction and wear or binding of the pins with the endsI of the toggle.

One object of this invention is to provide a brake expanding mechanism that is made up of a minimum of parts yet is simple and enicient in operation and may be readily assembled. Another object is to provide a vehicle brake wherein the cable for operating the brake expanding means is operatively connected to the brake expanding device exteriorly of the drum and is arranged to lie alongside the apron and in a plane parallel thereto. Another object is to provide a novel form of dust housing for enclosing the exposed parts of the brake expanding mechanism and the actuating cable. Another object is to provide a fitting in the dust housing for receiving one end of the cable conduit wherein such conduit end is securely and rmly gripped and is prevented from Withdrawal therefrom. Another object is to facilitate the operation of the spreading mechanism by relieving binding and shearing stresses on the thrust pins. Another object is to make for a relatively short (Cl. 18S-78) length of cable between the pull rodand the brake actuating mechanism. A

Figure 1 is a detail of one of the frontA wheels of a vehicle showing the arrangement of the brake operating cable and conduit alongside the apron. Y Y

Figure 2 is a detail showing my preferred form of linkage in inoperative position.

Fig. Zw is a view of a modied form of bell crank lever 2 showing a longer arm I0 than is 1o illustrated in Fig. 2.

Figure 3 is a plan view of a vehicle brake showing the non-parallel relation of the thrust pins connecting the expanding mechanism to the shoe ends when the shoe is in inoperative position.

Figure Llis a detail of the linkage shown in rFig. 2, with the toggle expanded. Y

Figure 5V is a plan view of the brake shown in Fig. 3 illustrating Ythe parallel relation of the thrust pins connecting the toggle ends to the 2o shoe ends when the shoe is expanded.

Figure 6 is aperspective View of one end of the dust housing showing the end fitting for the cable conduit.

Figure 7 is a vertical transverse section through 25 the dust housing.

Figure 8 is a view of the dust housing.

Referring to the drawings, I have illustrated my invention associated. with a brake mechanism which includes a full oating internal expanding brake shoe A having separable ends and an anchor B against which the shoe ends abut mounted on the apron C thatcloses the open face of the brake drum D, mounted to rotate within the swiveling wheel W. One of the shoe ends is provided with an adjustor E that is circumferentially adjustable with relation thereto to vary the -eiective length of the shoe, therebycomy pensating for wear of the brake lining. The toggle mechanism T for spreading the shoe is ar- 40 ranged between the adjuster and the opposite end of the shoe and serves to force such ends apart and expand the brake ring into engagement with the drum. The mid portion of the toggle is connected to a link I, which is in turn pivotally connected to one end of a bell crank lever 2 that has a sliding pivot as at 3 on the outer side of the brake apron C. All of the parts just mentioned are enclosed and protected from the elements either by reason of their position within the drum or by means of a housingH mounted on the apron and adapted to protect the parts operating thereunder from dust and dirt. The linkage just described is actuated to spread the toggle by means of a flexible cable attached to tends through a conduit C Vin a ttingF, Fig.

Vdust housing. Y .Y

The brake shown is preferably made up of T- section 'stock rolled into a split ring Vhaving separable ends. The radialV ange of the ring mayA be cut away at various'points, as shown, to'imiout toward the brake drum which causes the pin partv varying degrees of flexibility tol various sec'-Y tions of the brake shoe. VVAn adjustorE is mountedat one end ofthe ring having an arcuate'sur- Vfalce engaging the inner side of'Y the lining supporting part ofthe shoe.

The adjustor is made up of two plates 2l and 22, the plate 22 being deformed to provide a tubular opening 23 (Fig. 3) that restsrat an angle toV the vertical when the shoeis in aposition of` rest.' This opening 23 is adapted to receive and supporta thrust pin 24. VTheV pin'is retained therein'by compressing'an internally protuberant rib V25 in the stock which makes at the opposing endV of the shoe is'deformed to providev a similar tubular opening 23V that sup- Y ports a'thrust pin 21 in the manner just described. Y Thusthere are arrangedV at both ends of the shoe twoy thrust pins, one of which is set at an angle'to the other when the shoe is inoperativeV position` with both'of the ends'resting against vthe anchor; The purpose lof this will be hereinafter Y described.

The pins 2li,v and 21 perform a dual'purpose'of VVVengaging' the ends ofthe toggle and of carrying rollers for spacingthe shoerends laterally from.

the apron. Eachpin is providedY with an enlarged head and the pin A2l carries afreely ro-V tating pair of rollers 30, one above and one be- Y lowrthe male toggle arm 5. The pin 24fhasan enlarged head and carries a single roller 3| and pivotally and/slidably receives above andbelow the roller, the bifurcated ends yof the female Ytoggle arm 6. It willV be noted that the angle of the pin 24 causes the roller tobear against the toggle arm, but as the arm forces the shoe end outwardly, the pin tends to assume a vertical s Y Y position thus withdrawing the roller from cone tact therewith. Y

The inner ends of the toggle arms Aengage a common pivot pin 1, the'inner end of the arm 6 Ybeing pivotally connected thereto andthe male armEQhaving itsV inner end bifurcated to permit of both pivotal and sliding connection. Y,In Vthe v position shown in Fig. 4, it will be appreciated that the toggler is Aapproaching dead center and Y continued movementV might pull the toggle over' dead center.

Y 1 Y However, the extreme V.inner end 0f`the male arm 5 engages a connecting portion v32 of thefemale arm 6 and further inward movement-.of theryoke changes the pivot'point of the Vtoggle from the axis'of theY pin 1Y to the point of contact between the arm Band the connecting portions 32.

varms engagelthe pivot'pin Y1V whichV in turn is engaged by a link l connected to the bell crank 2 whichv is inturnconnected to an actuatingY cable 8. Tension on the cable tends to flatten and 21 in the direction of the apron. When the drum is rotated Vcounterclockwise whichis the intended rotation for Vforward movement of the a bearing with Y a groove 26 in the pin. Likewise, the radial ribY Asmentioned, ther inner ends of the rtoggle vehicle, spreading the toggle is intended to force the more flexible end of the shoe away from the anchor and into engagement'with the drum so g i ifthe right side of the band (Fig. 5) remainsY stationary, the opposingside of the band moves l 24 to be moved toward a position of parallelism withV the opposing pin until such time as the shoe is fully expanded at which time, the pins should beparallel. It will be noted that everir fraction of movement toward such parallel posi- Y tion tends to progressively decrease the severity Y Y of the frictional engagement between the pin and toggle arm, thus reducing the hazard of shearing or bending the pin and providing an easier acting toggle, OnV the other hand,.during the application of the brake, if the left side of the shoe remains stationary and the right side moves out, the pin 21 tends to Vmove toward angular position until suchrtime as it parallels the other pin, so that when the toggle is spread to its greatest extent, there is no binding between the toggle arms and the thrust pins.' .e Y

Returning to the toggle actuating linkage which forms themajor precept of this invention, one' end of the link l extends through a suitable openingY 9' inthe' apron C which is suflciently elongated to permit the link to oat back and forth in accordance with the movement of the shoe depending, of course,-fonxthe direction of drum rotation. The link is pivotally connected toione end I ofthe bell crank Vby means of a pin Il. The other end of the bell crank designated at vI2' Vis provided with an oiset I3 having anarcuate groove' lil in the marginal edge adapted to cooperate with the upset arcuate portion 3 formed at one end of the slot 9 in the apron C. YA stopY l5 adjoins the arcuate groove lll and is adapted to contact with the planular surface of the apron immediately in rear of the upset portioniS, to limit the movement of the bell crank. Y

This end l2 of the bell crank is also attached to a flexible cable 8 by means of yoke I8 that engages a pin El carried bythe arm that is spaced from and aligns with the pin li. The cable,

of course,V may be secured to the yokeY inrany ,Y manner desired,V although Vas shown, a tubular sleeve Vl 8 is provided as a part of the yoke assembly through which the cable end extendsV and isV secured on the 'opposing side thereof.

YAs for the operation, when'the cable is pulled with the'partsV in the position'rshowninV Fig, 2, the straight pull at the outer end of the short arm ofV the bell fcrank ,exertsa force thereon,l one ofY the'componentsY of whichV tends to pull thelink Vl VoutwardlyY through the slot il.' As the link moves outwardly, the bell crank as a whole shifts about the Vupset portion 3. The link,'oi course; is free ",to ilo-at in accordance with the movement of the brake band. The limit of movement'of the bell crank is determined by the'stop liwhich may beof any length desired toeiect Vthe desired degree of movement. Thus, when the .parts as- .sume the position shown in'Fig e,y thetog'gle has been spread to the pointV where the Secondary pivot between the arm 5 and connectingportion 32 Vbecomes effective, and the'sho-e spread into engagementV with the drum. Continued pulling Y Y yon the cable after 'the parts of thetoggle reachY 751 the secondary pivot, tends to straighten the linkage I and 2 and further flatten the toggle. When the tension on the cable is released, the springs distant from the radial center about which thel bell crank shifts, thus giving the bell crank a one to one ratio. However, the pivots may be spaced.

unequal distances to vary such ratio if desired as shown in Fig. 2a to eiect a greater movement of the toggle in response to a predetermined pull on the actuating cable and if desired to eifect a lesser movement of the toggle, the arm l0 of the bell crank 2 may be made shorter as shown in Fig. 2.

As hereinbefore mentioned, a dust housing H is provided for enclosing and protecting the exposed parts of the spreading mechanism, such as the outer end of the bell crank 2 and the end of the flexible tension element connected thereto. 'Ihis housing is made up of light durable stock and is substantially rectangular in cross section through its middle portion, Fig. 7, having an open side adjacent the apron. The main body of the housing is provided with tabs or ears 52 that are formed integral with opposite marginal edges thereof and are turned back so as to lie normal with the plane of the apron. These tabs may be bolted to the apron by means of bolts 5|. An additional tab 53, Fig. 4, is formed integral with the rear wall and may also be bolted to the apro Thus, it can readily be seen that by the removal of these bolts the dusthousing may conveniently be removed to permit access to the parts of the actuating mechanism enclosed thereby.

One end of the housing is bent to form a neck 54 that is substantially tubular in cross section in its upper portion as at 55 and rectangular in cross section in the lower half 56 thereof. The lower wall of the rectangular section is split longitudinally to provide two inturned flanges 57 separated by a slight clearance, the whole being adapted to be drawn together by a bolt 5S mounted in the lower section.

The tubular portion 55 is adapted for telescopic engagement with the tubular member 59 formed as a part of the conduit end fitting and adapted to be carried by the housing. This end fitting comprises a perforated member 60 adapted to overlie the open end of the housing and has spaced wings 6I formed on the lower end thereof that are adapted to engage with the walls of the housing dening the rectangular portion 56 to thereby prevent rotation or relative lateral movement with respect thereto. The tubular portion 59 is also split longitudinally as at 62 and is provided with a perforated end wall 53 against which the conduit end is adapted to abut, the remainder of the conduit within the tubular portion being snugly embraced by the wall sections. After the fitting is assembled on the end of the conduit it may be telescoped on the end of the housing and the bolt 58 drawn tight. This tends to compress the wall dening the tubular portion 55 of the neck 54 and collapses the tubulariportion 58 of the fitting around the conduit end to effect the firm and snug embracing thereof. Of course, the flanges 51 act as stops to prevent the application of excessive pressure to the conduit.

This assembly is quite simple and is very ef# fective in securelygripping the endof the conduit adjacent the drum. It is also effective in preventing the twisting or turning of the end inasmuch as the wings 6| prevent relative lateral or rotational movement of the fixture with respect to the neck of the housing.

The foregoing description is a description of a preferred form of my invention to which Ido not care to be particularly limited, nor do I care to be limited in any manner other than by the claims appended hereto.

I claim:

1. In a brake, the combination of a drum, an apron, a brake shoe formed as a split band and having a radial flange, an anchor taking torque from saidv shoe, depending on the direction of drum rotation, a toggle arranged between the shoe ends for spreading the ends of said shoe apart, a link connected to the center of said toggle, a bell-crank lever having a shiftable pivot on the apron, said lever being connected to said link and means for actuating said bellcrank to spread said toggle.

2. In a brake, the combination Aof a drum, an apron, a brake shoe formed as a splitring and having a radial and a peripheral flange, an anchor for taking torque from either end of said shoe depending on the direction of drum rotation, a toggle arranged between the shoe ends for spreading said ends apart, means for actuating said toggle comprising a cable actuated linkage including a bell crank lever pivoted on the apro-n.

3. In a brake, the combination of a drum, an apron, a brake shoe formed as a split ring and having a radial and a lining supporting ange, an

anchor arranged between the shoe ends for taking torque from either of said ends, means for spreading said shoe apart, and means for actuating said spreading means comprising a cable actuated linkage including a lever having a sliding pivot on an upset portion of the brake apron.'

4. In a brake, the combination of an apron, a drum, a brake shoe having separable ends, an anchor for taking torque from either of said ends, a toggle mechanism located between the ends of said shoe for spreading'said ends apart, a link connected to the center of said toggle, a bell crank having a long and a short arm ,connected to said link and having a sliding -pivot on said apron, and a cable connected to the short arm of said bell crank.

5. In a brake, the combination of an apron, a'

brake drum, a shoe laterally disposed with relation to said apron, means for spreading said shoe apart comprising a toggle and cable actuated mechanism including a bell crank lever slidably and pivotally mounted on the apron for spreading said toggle.

6. In a brake, the combination of an apron, a brake drum, a shoe laterally disposed with relation to said apron, means for spreading said shoe apart comprising a toggle and cable actuated mechanism for actuating said toggle including a bell crank lever lying partly within and partly without the drum and having a sliding pivot on the brake apron.

7. In a brake, the combination of an apron, a floating brake shoe formed as a split ring and from T-section stock having a circumferentially adjustable end portion, an anchor for taking torque from either of said shoe ends, means for spreading said ends apart and actuating. means for said spreading means including a bell crank lever slidably and pivotally mounted on the apron Vthereof adjustable to` vary and-connected exteriorly of said drum to a flexible pulling member.

8. In a brake, the

Y said part exteriorly of ,theiapron V9. In a brake, the combination of 'an apron, al drum, a floating frictionband within said drum having separableV ends and having a portion ad- Yjustable to vary Vthe effective length of the shoe,Y

an anchor arranged-between theshoe ends for taking the torque therefrom, a floating ,applyingV device arranged between YtneshoeY ends and ac-` Y tuable, to spread said ends apart to apply the linkage including ailever on the apron.Y`V

' to said friction device, an upright position w Y drum,

brake, and a flexible tension element lying eirteriorly of the drum and in the'plane of the apron and operatively connected'to said iloating applyi ing device exteriorly of said drum byrmeans of a having a sliding pivot l0. In a brake, the combination of an apron, a drum, an anchor, a friction device disposed within said drum having separable ends, a means arranged betwecn said separable ends for spreading said shoe, said means comprising a pair of arms actuating the friction device, acontrol for actuating said arms, said control comprising a Vlink pivotally connected to oneV of said arms and operatively connected to a bell crank lever having a'sliding pivot on Vthe brake apron.

11. In a brake, the'combinationV of an apron, aV

an anchor, afriction device located'rwithin T-section stock jand hav-V ing separable ends, a toggle,V arranged betweenY drum, Y said drum formed from said ends, thrust pinsV for connecting saidV toggle one of said pins assuming en said band is in inoperativepcsition and the other of said pins being set frat an angle thereto.

12. In a brake, the combination of an'apron, a

means for spreading 'said shoe ends apart and means for connecting said spreading means to said shoe ends comprising thrust pins,'one of which isY disposed at an angle to the otherv when the shoe is in inoperative position andtends to `lie substantially parallel therewith when saidrshoe is in operative position and expanded into frictional engagement with the drum.

13. In a brake, the combination of an apron', a vbrake drum, a brake shoe having separable ends, a toggle for spreading said shoe apart arranged Y betweenV said ends, means for connecting said togglerto saidbrake shoe comprising thrust pins that are angularly disposed when the brake'shoe is in a position of rest, and means for actuatingV i said toggle comprising a *cable operatively con nected to said toggle and a bell crank slidably pivoted onsaid apron. Y Y

14. In a brake, an apron, a Vbrake'drum, a

brake shoeV having separable ends and a lining supporting flange, YVa toggle for spreading Ysaid combination of an apron, aV drum, a floating friction band within said drum the effective length f a floatingY brake shoe disposed laterally toY said apron and being formed as arsplit band,V

shoe, thrust pins for connecting'r said toggle to relation to one another and meansfor actuating said toggle comprising a linkage including a bell crank lever having a sliding pivot on the apron and an actuating nected thereto exteriorly of 15. Inra vehicle brake,

said-"drum, the combination of a brake drum, an apron, a friction device locatedV drum, having separable ends, actuat-VV within said Y ing Vmechanism for said device, an anchor against which said ends abut, a cable for actuating said Yilexible tension yelement con- Y Y said shoe, said pins being angularly disposed with friction device, said cable extending through a. 'Y

conduit and beingV connected to said actuating Vmechanism exteriorly of the drum, ,a housing mounted onV the apron and Venclosing saidY point of connection, and means'for securingsaid con- Y duit to saidhousing, saidV means comprising a tting encompassing the end of said conduit and`Y 1 Y Y Y Y 2O clampedin said housing. Y Y 16. In'V a vehicle brake, the combination of a brake drum, an ap1'ona friction device located within said drum, havingV separable Yends, actuating mechanism for Ysa1d-device, an anchor against which said ends abut, aY cable for actuat-V ing said friction device,v said Ycable extending through a conduit and 'being' connected to said actuating mechanism exteriorly of the drum, a housing mounted on the apron and enclosing said point of connection, and means for securing said conduit to said housing,rsaid ymeans comprising a duit and telescopically engage with said housing.

17. In a vehicle brake, the combinationV of aV brake drum, an apron, afriction device locatedV Vpart adapted to encompass the end of'said conj within said drum, having separable ends, actuating mechanism for said device, an anchor'ag'ainst which said ends abut, a cable Yfor actuating said friction device, said cable extendin'g'througha ccnduit and being connected to said actuatingv loy mechanism exteriorly of the drum, a housing Y mounted onV the apron and enclosingsaid point of connection, and means for securing said con#r f duit to said housing, said means comprising a part engaging the end of Vsaid vconduit and insertable intosaid housing and Ymeans for clamping said housing therearound; Y

18. In a vehicle brake,

Vthe combinationof a brake drum, an apron, a friction devicelocatedV within said drum, having separable ends, actuating mechanism for said device, an anchor against which said ends abut, a cable for actuating saidfriction device, said cable extending through a conduit and being connected to said actuating mechanism exteriorly of the drum, alhousing mounted on the apron, and enclosing said point f Y of connection, and meansforY securing said conff duit torsaid housing, said means comprising a sertable into said housing, being'held therein by clamping the walls of said housing therearound.

Vpartenga'ging the Vend of said conduit and in-w Y,

19. In a vehicle brake, the combination of a i brake drum an apron,` a friction device ,located within said drum, having separable'endsractuating mechanism for saiddevce, an anchor againstV Y which said endsabut, a cable for actuating said friction device, said cable 4extending through a conduit and being connected'to said actuating Y l mechanism exteriorly of thel drum, a housing mounted on the apronrand enclosing said point of connection, and means for securing said con- Y duit to said housing, said means including'apart having a tubular portion for Yencompassing saidAV conduit and telescopicallyf engaging with said fi i 75 housing. Y Y Y 20. A brake comprising, in combination, a friction element having separable ends, an apron adjacent said friction element, means for separating the ends of said friction element including a part pivotally and bodily slidably engaging said apron, and means engaging said part for actuating said means for separating the ends of the friction element.

2l. A brake comprising, in combination, a drum, an apron having an anchor pin mounted therein, a friction device having separable ends abutting `against said anchor, means for spreading said ends apart, a flexible cable for actuating said means, means between said cable and Ysaid spreading means for transmitting force therebetween, said means including a lever having a long arm and a short arm, said short arm being connected to said cable, said long arm being associated with the spreading means, said lever being pivoted on the apron.

22. In combination with a brake comprising a brake shoe having separable ends and means for separating the ends of said shoe, a pair of thrust pins for connecting said means to said shoe, said thrust pins being mounted one at each end of said shoe and being angularly related when said shoe is in inoperative position and in substantial parallelism when said shoe is in operating position.

23. A brake comprising a drum, an apron, a brake shoe disposed Within said drum in combination With a thrust pin carried by said brake shoe, said thrust pin having a groove therein, said brake shoe having a portion co-operating With said groove for supporting said thrust pin.

24. A brake comprising, in combination, a brake drum, an apron, a brak-e shoe having separable ends located Within said drum, said ends having tubular openings normal to the horizontal axis of the brake shoe, thrust pins mounted in said tubular openings, said thrust pins being supported through engagement with a. deformed portion of the Wall of said openings.

25. In a brake, the combination of an apron, a drum, a brake shoe disposed laterally to said apron and being formed as a split band, means for spreading said shoe ends apart, means for connecting said spreading means to said shoe ends comprising thrust pins, one of which is disposed at an angle to the other when the shoe is in inoperative position, said thrust pins being supported by said shoe ends and being secured thereto by deforming a portion of the shoe therearound.

26. In a brake, the combination of an apron, a brake drum, a brake shoe having separable ends, means for spreading said shoe ends apart, thrust pins for connecting said means to the ends of said shoe, said thrust pins being angularly related one to the other when the shoe is in inoperative position and which tend to lie substantially parallel when the shoe is in operative position, said shoe ends having portions adapted to receive and encompass said thrust pins, said pins being secured in position by deforming a portion of said shoe therearound.

27. In a brake, an apron, a brake drum, a brake shoe having separable ends, means for spreading said shoe, thrust pins for connecting said means to said shoe, said pins being angularly disposed with relation to one another when said shoe is in brake release position and in substantial parallelism when said shoe is in brake applying positions.

28. In a brake, an apron, a brake drum, a brake shoe having separable ends, means for spreading said shoe, thrust pins for connecting said means to said shoe, said pins being angularly disposed with relation to one another when said shoe is in one position and in substantially parallelism when said shoe is in another position, means for actuating said spreading means including a lever pivotally connected to the apron and a iiexible force transmitting device connected to said means.

29. In combination with a vehicle brake having an apron, a housing secured to said apron `having a deformable neck, a flexible force transmitting device including a conduit located within the neck of said housing and means for securing said conduit to said housing by clamping said neck therearound.

30. In combination with a vehicle brake having` an apron, a brake shoe and means for actuating said brake shoe having la part lying exteriorly of said apron, of a housing overlying said part and having an open end With a polygonal portion, a exible force transmitting device including a flexible tension element connected to said part, and a conduit lying Within the open end of said housing and means for clamping the end of said housing to said conduit, said conduit having a part to engage the polygonal portion to prevent accidental turning of the conduit upon the housing.

RUSSELL S. BEGG. 

